feat(ultraplan-local): v1.6.0 — /ultraresearch-local deep research command

Add /ultraresearch-local for structured research combining local codebase
analysis with external knowledge via parallel agent swarms. Produces research
briefs with triangulation, confidence ratings, and source quality assessment.

New command: /ultraresearch-local with modes --quick, --local, --external, --fg.
New agents: research-orchestrator (opus), docs-researcher, community-researcher,
security-researcher, contrarian-researcher, gemini-bridge (all sonnet).
New template: research-brief-template.md.

Integration: --research flag in /ultraplan-local accepts pre-built research
briefs (up to 3), enriches the interview and exploration phases. Planning
orchestrator cross-references brief findings during synthesis.

Design principle: Context Engineering — right information to right agent at
right time. Research briefs are structured artifacts in the pipeline:
ultraresearch → brief → ultraplan --research → plan → ultraexecute.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/rules/agent-development.md

@@ -0,0 +1,27 @@
+---
+paths: agents/**/*.md
+---
+
+# Agent Development Rules
+
+## Required Frontmatter
+
+All agent files MUST include this frontmatter:
+
+```yaml
+---
+name: descriptive-name
+description: |
+  Multi-line description of when to use this agent.
+model: opus|sonnet|haiku
+color: blue|green|yellow|purple|cyan|magenta
+tools: ["Read", "Glob", "Write"]
+---
+```
+
+## Conventions
+
+- Agent names use kebab-case with `-agent` suffix
+- Description must explain WHEN the agent should be used
+- Model choice: opus for analysis, sonnet for implementation, haiku for scanning
+- Color must be unique within the plugin